Trying to improve earth ground.

Been lurking here for a while. I got an HDTV for Christmas, and
almost got sucked into the false security of point of use surge
protectors. Anyway, I need someone to explain something to me.
I have been doing alot of research on surge protection. My plan was
to improve my earth ground (my house is 35 years old), and then get a
whole house surge protector installed. Luckily, my CATV, Phone, and
Power all come in right next to each other. There is a small pipe that
comes straight down out of the meter box that contains a bare ground
wire. I assumed that this wire went from the meter box to a cold water
pipe underneath the house. My plan was to replace the wires coming from
the cable grounding block, and the telco box with bare 6 gauge copper
wire (which I did), and disconnect the ground wire from the cold water
pipe, and attach everything to a new 8' copper grounding rod. Turns
out that the wire coming from the meter went underneath the house to
the switchbox. There was about 2 feet of slack buried in the ground
with a rusted out grounding rod clamp attached to it. There was also a
grounding rod there that I hadn't seen before. I'm guessing that at one
point the wire was attached to the grounding rod.
Anyway, my question is, is this a typical setup? I know a good bit
about "post switchbox" wiring, but not alot about what happens before
there. This may very well be the way it's supposed to be, but for some
reason, I was thinking there would be two grounding wires.
Since there was no way to slide on a grounding rod clamp, I went back
to Lowe's and bought a cold water pipe clamp, and clamped all three
wires to the existing ground rod. With ALL that being said, what is the
best way to improve my earth ground system? Is this enough? I REALLY
want to protect my new electroinics.
One more thing.... The breaker that controls the outlet that the TV is
plugged into is not in the main switchbox. For some reason, it is in a
smaller switchbox along with the downstairs A/C, outside. I don't know
if this affects anything. Thanks in advance!!!!!
- Mike

"In a continuous UPS, the computer is always running off of battery
power and the battery is continuously being recharged. You could fairly
easily build a continuous UPS yourself with a largish battery charger,
a battery and a power inverter. The battery charger continuously
produces DC power, which the inverter continuously turns back into
120-volt AC power. If the power fails, the battery provides power to
the inverter. There is no switch-over time in a continuous UPS. This
setup provides a very stable source of power.
Standby UPS systems are far more common for home or small-business use
because they tend to cost about half as much as a continuous system.
Continuous systems provide extremely clean, stable power, so they tend
to be used in server rooms and mission critical applications. "
says
http://computer.howstuffworks.com/question28.htm

The small UPS systems (350 watts and up) are nice. They are intended to
keep your computer running only long enough to shutdown smootly,
typically a minute or two. Also, note the batteries in those units only
last about 2 years and replacements cost the same a replacing the whole
unit.

Mike
Improving the earth ground is a project for a very well educated and
experienced DIYer or a well qualified electrician. The effective
grounding electrodes that can be added to your home are a ground ring or
stacked driven rods.
Stacked driven rods are easier to install but they require parts that
are not readily available. You will need four or five rods and the
appropriate rod couplers. These can be special ordered by an electric
supply house. You then go to a rental store to rent an electric jack
hammer and a ground rod cup. Using the electric hammer you drive the
first rod into the earth at least the distance away from the house that
the footer is under the ground. If the footer is eight feet down then
the rod should be eight feet out from the foundation wall. If you are
using threaded rods you drive them with a screw on driving cap so as not
to damage the threads. If you are using threadless couplers you apply
the first coupler before driving the first rod. After you have driven
the first two or three rod sections so that you are twenty to twenty
four feet down you measure the resistance to earth of your electrode by
using a ground loop impedance tester in urban areas or a fall of
potential ground tester in less built up areas. Those meters can be
rented from a rental company that specializes in the electrical
contracting industry. These are usually found only in larger cities.
Larger or specialized electrical contractors would also have them as
part of the firms equipment. You keep adding stacked rods until the
impedance of the total rod is less that twenty five ohms or less than
five ohms if you want the equivalent impedance of a municipal water
system. Depending on the soil and substrates this can take from two
hours to all day. I have done electrical work that required
specification level grounding for over thirty years. I have never seen
two parallel rods have a lower resistance than the same two rods stacked
by using a rod coupler and I do mean not once. In very rocky soil you
will need one inch rods in place of the usual 5/8" ones. Thickly clad
copper weld rods are the only type that is likely to maintain its
conductivity over time in most soils. Should you strike true rock
bottom before reaching the desired impedance you must either resort to
paralleled rods or install a ground ring.
A ground ring is a bare copper conductor that encircles the building at
a depth of bury of at least 30 inches. To be fully effective it should
be buried below the permanent water table. As you can see that is a lot
of work. If it must be a ground ring then you will want to use a ditch
witch or a similar trenching machine to dig the trench clean around the
building. A shorter length of buried conductor might work but you can't
test it until it has been back filled and very well tamped preferably
with a mechanical tamper. It will take weeks for a ground ring to reach
it's lowest impedance so you should plan to go all the way around the
home. Bury the ring conductor as deep as the trencher will go rather
than settling for the minimum required by code.

--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous

I'm beginning to realize that after today. I'm thinking of having an
electrician come out and look at everything, measure ground resistance,
improve my earth ground, etc. I don't think that it will take too many
stacked rods; I live in a wooded neighborhood (everything stays a
little damp), and the soil composition is clay. One good thing that
came out of all of this is that I realized that my "earth ground" was
really 2 feet of slack buried about 6 inches under the ground.
I'm not intimidated by projects like this, I've done some pretty
involved DIY stuff before (tile floors, plumbing, etc.), but I want to
make sure that it is done right. Overall, I think that it will be a
good investment. Like I said before, I live in a wooded neighboorhood
that is prone to lightning strikes. I've lost a cable modem and a fax
machine in the 2.5 years that I have been here. Another thing that has
amazed me is the abundance of misinformation about surge protectors.
Tom, no offense to your profession, but do you think that most
electricans will do something similar to what you recommended, or just
drive a new rod and say it's grounded?

No offense taken by me because in this regard my profession needs
offending. Most electricians know the code requirements and how to
apply them. It is a rare customer who is willing to pay for anything
more. Talk to several electricians. If they own a ground impedance
tester that is a start.
You said that the Grounding Electrode Conductor (GEC) from the meter can
goes to the main panel in your basement. Are you sure about that or
does it go to an underground metal water pipe first? In any case the
Grounding Electrode Conductor should not run from the meter can to the
main panel because when wired like that it is a parallel path for
neutral current. Some utility companies require that the ground rod be
attached in the meter can while others absolutely forbid the practice.
The code allows you to make the connection of a GEC at any point on the
neutral between the end of the utility's service drop or lateral and the
enclosure of the Service Disconnecting Means. The Service Disconnecting
Means is the first switch, breaker, or fuse pull out that will
disconnect the power to the building. There can be up to six such
devices needed to deenergize a residential service. Best practice is to
run a single GEC to the nearest electrode and from there to the next
nearest and so on. That makes the point of attachment of the GEC the
single grounding point for that electrical service. It is fairly common
to find two or more GECs that are attached to the neutral at different
points especially were the utility requires a ground rod at the meter or
in lightning prone areas were the GEC for the ground rod is often
attached at the service head. This is also common practice in
situations were the two electrodes are in totally different directions.
What should not be done and may be the case in your situation is that
the GEC should not run in parallel with any portion of the neutral
conductor.

--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous

I got a question for you.
Assuming a house is grounded to water pipes in a city water system,
and an electrical problem developes, which is sending a voltage into
the water pipes, but not enough to trip the breaker. Also assuming
that the water mains and laterals supplying the homes are all metallic
pipe (copper, steel, lead, etc), Can someone in a neighboring house
get shocked when they touch their plumbing? I believe most newer
houses have plastic laterals, but in the past they used copper and
before that, lead. Connected to steel water mains.
Also, if a person has a well with steel casing, is that well casing
not the best possible ground anyone could have?

I think that's possible. Years ago I was bench testing a motor in my garage
and got a shock. I found nothing wrong with the motor, so I took a brand new
motor out of the box and the same thing happened. Turns out that the rear of
my old fuse panel was shorting out, causing voltage to be sent through the
earth.
wrote:

A shock to a person in an adjacent home is unlikely because the
Grounding Electrode Conductor in that home is attached to the metal
underground water pipe and to the neutral of their service. That
provides a lower impedance pathway for the neutral current to get back
to the transformer. It would take several simultaneous failures for a
shock hazard to develop.
A deep drilled well with a metal well casing is indeed an excellent
grounding electrode. A municipal water system with it's miles of
undergorund metallic piping is often of lower impedance then even a deep
driven well's casing.

--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous

The problem with the well casing is the impedance, as Tom alluded to.
For a safety ground it is excellent, for lightning protection it can
be marginal. Lightning is not a DC current but acts more like RF and
a single long grounding conductor can act as an inductor. I always
prefer multiple ground rods spaced at least twice the length of the
rods apart, and connected with large stranded copper wire. Using bare
wire can be helpful, but will also raise the possiblilty of the soil
corroding it away over time.

Voltage drop form a ground rod drops off rapidly away from the rod. A
post quited IEEE 142, Recommended Practice for Grounding of Industrial
and Commercial Power Systems as 52% of the total ground resistance
within 6 inches of the ground rod and 75% of the total ground resistance
within 3 ft of the ground rod. Why space the rods 2x, and why base it
on length, not fixed distance. Longer rods should drop off as fast with
radius. If concerned with long grounding conductor would multiple rods
connect back with separate grounding electrode conductors. Any reference
to the above or impedance?
bud--

You can mail-order coupled grounding rods, threaded or tapered, from
McMaster Carr Industrial Supply, www.mcmaster.com They'll typically
have them to you anywhere in the U.S. within a few days. Not the
cheapest hardware supplier, but very reliable, and much easier to
deal with than shop droids who say anything that isn't in stock
doesn't really exist.

Why not drive next to the building since you are using multiple rods and
will pass the footing? That would reduce the conductor length and put it
all in a more protected area. If away from the building can you use
shallow burried #4? If aiming for 5 ohms should grounding electrode
conductor be full size as for water pipe?
If a single rod is driven next to the building, as is common practice,
only about half of the rod faces dirt. If the foundation was wood
(insulator) I would think the ground resistance would be double that for
a rod in the middle of the yard. For concrete walls is there conduction
along the wall that lowers the resistance? Seen any information along
these lines?
For a single rod I would think driving through the basement floor
(misisng the footing) would give a lower resistance. The rod has earth
all the way around, is not in frozen ground part of the year and is
lower in the earth and likely nearer wetter soil or ground water.
Probably should be 10' to put the required 8' in contact with the earth.
Great description of coupled rods and installation.
bud--

I've always driven them away from the footer and only part of that is
electrical. The backfill near the footer often contains a lot of trash
that will block or distort the driven rod.
Even at lower resistance the EGC need not be larger than Number two
according to the papers that I read so many years ago.
As for driving through the basement floor that works during construction
but after that it is usually too difficult to drive them in a basement
with ceilings less than twelve feet.

--
Tom Horne

Well we aren\'t no thin blue heroes and yet we aren\'t no blackguards to.

Mike,
Electrical Grounding by R. P. O'Riley, Delmar publishing, is pretty good
at explaining this stuff. Sounds like the bad clamp at the electrode may
have been your problem so measure the resistance of the grounding system now
that you have corrected this. You should probably check with the various
utilities before you hook their equipment to your ground. And be sure that
your ground is not close to your lightning rod ground.
Dave M.

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